Ondatra sp.—Muskrats

†Ondatra idahoensis Wilson 1933—Idaho Muskrat

Fossils of Ondatra idahoensis are widely distributed in the U.S., but the species is
represented in New Mexico only by a palate with complete dentition from the Kelly Canyon site. It
is well represented in the Arizona late Blancan and in southern California.

Ondatra zibethicus (Linnaeus 1766)—Common Muskrat

The semi-aquatic Common
Muskrat relies on aquatic vegetation, and their lodges or other denning sites are protected by
water. Presence in a fossil locality indicates permanent water within the range of "site
capture." Muskrats are relatively large, with only medium or large mammalian predators or
large raptorial birds apt to move prey far from the site of the kill. Most skeletal items are
easily identified. Thus, unlike many smaller mammals, presence in the fossil sample is unlikely to
go unnoticed.

Fig. 1. Common Muskrat. US Fish & Wildlife Service photograph by Dave Menke.

Although most records are from sites close to current bodies of water or known Pleistocene
lakes, the Baldy Peak presence presumably documents a period of time during which the Mimbres River
was an active stream far south of where it currently is permanent.